I'm looking to add Borax to my newly refilled pool (it was just too much of an algae mess so I bought a submersible pump, drained and refilled). My TA has always been high due to our city water and I managed to get it down from 200 to about 150 over the last few weeks by adding muriatic acid daily and aerating, but it's been tough trying to keep the PH down to 7.2 -7.4 as it keeps jumping back to 8.0 by the next day.

To aerate I set up my submersible pump attached to a pvc pipe in the deep end to shoot water into the air but the splashing was too noisy (have to keep the neighbors happy) so I put an elbow joint on it and now have a 'periscope' sticking up out of the water. (Hey mister, there's a submarine in your pool!). At least now when I add acid to the deep end it should be getting quickly dispersed by the pump down there.

So my question is, how low do I need to get the TA before I can start adding Borax? It says in the sticky: "If your TA is over 140ppm, or your CH is over 400 ppm, ASK, before you start this process." My CH is 200 ppm so I'm good there.

Seems like I'm using a lot of acid just getting the TA down, then I'll have to use even more when I start adding Borax. Have to wonder if the pool store employees think I have some sinister purpose buying all this acid, but they seem to be the only ones with the 31.45% strength. Lowes and Home Depot only sell the Kem-Tek 15% mix, and for the same price, so you are paying twice as much.